VOLUME 41, NO6, DEC-2019

Synthesis of Soluble and Highly Thermally Stable Polyaniline- Titanium Dioxide Composite via Inverse Emulsion Polymerization

Polyaniline (PANI)/Titanium dioxide (TiO2) composites were prepared by polymerization of aniline in the presence of TiO2 using inverse emulsion polymerization protocol. In this method 2-butanol and chloroform were used as dispersing media and the materials were tested for corrosion protection of stainless steel in Indian Ocean water. The amount of aniline, oxidant (Benzoyl peroxide), Dodecylbenzenesulphonic acid (DBSA) surfactant and metal oxide (TiO2) were varied in the reaction bath for optimum yield. The as-synthesized PANI and PANI-TiO2 composites were soluble in a number of common organic solvents and characterized with Ultravilot-visivble (UV¬-Vis) and Fourier Transform Infra-Red (FT-IR) spectroscopies. The surface morphology, particle size and crystinality were determined with Scanning Electron Microscopy (SEM) and X-Rays Diffraction (XRD) analysis. Thermogravimetric analysis (TGA) was employed to determine thermal stability of the composite. The total mass loss was found to be 58% in PANI as compared to 22% in PANI-TiO2 showing comparatively higher thermal stability of the composites. The composites were electrochemically active in acidic medium and reduced corrosion rate of steel to 0.9083 mm/ year Indian Ocean water. Finally it was concluded that PANI-TiO2 composites could be employed as anticorrosive coatings for steel in aggressive corrosive environmentread more

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Anwar-ul-Haq Ali Shah, Saima Shaheen, Muhammad Kamran, Humaira Seema Rizwan Ullah and Salma Bilal

Structural, Elastic and Electronic Properties of γ˝ Phase Precipitate in Mg-Gd-Zn Alloy

The γ˝ phase (Mg4GdZn) precipitate in Mg-Gd-Zn alloy was calculated via first-principle density functional theory within the generalized gradient approximation. Through structure optimization of full relaxation, the lattice parameters were theoretically obtained, and the calculated Mg4GdZn is the most energetically stable in view of the formation energy. Independent elastic constants were also calculated, illustrating the calculated Mg4GdZn is mechanically stable. The shear modulus, polycrystalline bulk modulus, Poisson ratio, and Young’s modulus of Mg4GdZn were calculated via the Voigt-Reuss-Hill approximation. Elastic anisotropy and ductility were analyzed in details. Seen from their charge density distribution and electronic density of states, both metallic bond and covalent bond were found in Mg4GdZn.read more

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Mengmeng Wu, Rongkai Pan, Jilei Liang, Guohai Zhou, Li Ma and Chunyu Zhang

Quantification of Riboflavin and Pyridoxine in a Mixed Solution at a High Concentration by Fluorescence Spectrophotometry

A new method of quantifying the contents of riboflavin (RF) and pyridoxine (PY) in their mixed solution was introduced in this study. A mathematical model was established to calculate the actual concentration of PY (Z) based on the apparent concentrations of PY (Y) and RF (X), which were quantified directly when RF and PY were mixed together. First, a linear relationship was found between Y and Z with a high coefficient, which defines fluorescence quenching efficiency. Second, a curvilinear equation was established between the apparent concentration of X and the fluorescence quenching efficiency (k) of PY. The actual concentration of PY could be obtained by using the two equations. The established mathematical model was verified, and the relative error of the calculated PY value was below 2.5%. The upper limit of fluorescence spectrophotometry quantification was up to 20 μg/mL for both RF and PY. Compared with RP-HPLC, this method is convenient in terms of sample pretreatment, as well as saves organic solvents and time.read more

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Xiaofei Li, Zhihua Wu, Shenguang Tong, Ping Tong, Xin Li, Anshu Yang and Hongbing Chen

The Selective Oxidation of Hydrocarbons on Isolated Iron Active Sites under Ambient Conditions

The N-doped carbon material supported Fe catalysts were developed for the oxidation of C-H bond of hydrocarbons to ketones and alcohols. The supported Fe catalysts were prepared by pyrolysis of [CMIM]3Fe(CN)6 ionic liquid in activated carbon. And the Fe(Ⅲ)@CN-600 showed good activity and high selectivity for the oxidation of alfa C-H bond of alkylbenzenes. The isolated Fe(Ⅲ) iron active sites should be responsible for the high activity and selectivity for the oxidation of hydrocarbons to ketones. Several ketones were obtained in good to excellent yields. Moreover, cyclohexanone can also be obtained through the oxidation of cyclohexane.read more

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Zhengliang Qi, Junmei Liu, Wanwan Guo and Jun Huang

Surface Properties of Whey Protein Gels

Surface properties of whey protein gels are reviewed based on traditional microscopic techniques and new methods, as optical profilometer and contact angle measurements. Optical profilometer is an instrument allowing measurement of surface roughness and contact angle measurements to determine the surface wettability behavior (hydrophobicity/hydrophilicity) of the gels. Investigation of surface properties of whey protein gels is very important, as it can transform this product to a new level of application. It could be used as a matrix for an active ingredient release, material for tissue engineering, e.g. scaffolds, i.e. temporally structures biodegraded in the human organism.read more

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Salvador Perez Huertas, Konrad Terpiłowski and Marta Tomczyńska-Mleko

Effect of Gamma-Irradiation on Properties of Polymer/Fibrous/Nanomaterials Particleboard Composites

This investigation aimed to study the role of different contents of nano-slag, as well as various doses of gamma-irradiation on physical and mechanical properties of rice husk-polyvinyl chloride particleboard composites. Equal proportions of rice husk fibers and polyvinyl chloride polymer were used. The treatment of rice husk fibers with silane coupling agent showed a significant improvement in both mechanical and physical properties of the prepared particleboard composites as compared to those containing untreated rice husk fibers. Moreover, the partial replacement of polyvinyl chloride with different percentages of nano-slag namely 5, 10, 15, and 20% by the weight of polymer manifested a good effect on the properties of the resulting particleboard composites precisely at 10%nano-slag. In addition, the effect of different gamma-irradiation doses on the properties of the particleboard composite specimens that contain 10% nano-slag showed an enhancement in the physical (thickness swelling %) and mechanical (flexural strength, and hardness) properties. In addition, the results elaborated that the irradiated particleboard composites had a good thermal stability.read more

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M. M. Younes, H. A. Abdel-Rahman and E. Hamed

Investigation of Low Formaldehyde Easy-Care Textile Finishes on Dyed Cotton Fabric

Crosslinking of cellulose is considered a necessary process in creating anti-wrinkling cotton fabrics. In the recent years, the concern of buyers regarding the wrinkle-resistant fabric has increased the demand of easy-care finishes. Formaldehyde based easy care finishes are carcinogenic but still used in the textile industry. Low formaldehyde reagents are being developed and tested to replace formaldehyde based easy care finishes. In this research the low formaldehyde easy care finishes; Fixapret ECO and Alkaknit WFR were investigated for their effect on color fastness to crocking, tear strength, tensile strength and durable press rating. Findings of the research showed that the there was a subsequent decrease in tensile and tear strength as compared to original fabric with the increase in resin concentration on both type of dyes. From the results we can say that higher the resin concentration, better the washing durability. This is due to the fact that resin decreases the chance of fiber chain displacement. The fabric with navy blue dye displayed much better performance and compatibility with non-formaldehyde resins as compared to turquoise blue dye.read more

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Nabeel Rizwan, Abdullah Ijaz Huassain, Syed Makhdoom Hussain, Muhammad Ansab Zaeem and Shahzad Ali Shahid Chatha

Quality Evaluation of Canola Oils and Deodorizer Distillate during Industrial Processing

Aim of present study was to evaluate quality of three collected sets of canola oil containing crude oil, neutralized oil, bleached oil, deodorized oil and canola oil deodorizer distillate (DD) form three different edible oil processing industries. Physiochemical properties such as moisture, color, free fatty acid (FFA), acid value (AV), peroxide value (PV), p-Anisidine value (AV), total oxidative (totox) value, saponification value (SV), iodine value (IV), unsaponifiable matter and soap content were evaluated. The results of the present study indicated that each stage of processing has different impact on the determined quality parameters. Overall processing was well controlled and final product i.e. refined, bleached and deodorized (RBD) canola oil was found to be fit for human consumption. Only soap contents should be further controlled during neutralization process to avoid extra processing time and losses in the bleaching process. High FFA contents in DD samples indicated that it could be used as a potential and cheap source for biodiesel production.read more

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Hadia Shoaib, Sarfaraz Ahmed Mahesar, Saeeduddin, Parisa Jafarian, Razieh Niazmand, and Syed Tufail Hussain Sherazi

Development of Extractive Spectrophotometric Methods for the Determination of Iron(III) with Dimercaptophenole and Heterocyclic Diamines

Dimercaptophenole (DM) is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of Fe(II). DM in the presence hydrophobic amins reacts with Fe(II) in the pH range 5.3 -7.2 to form a coloured complex. Chloroform, dichloroethane, and carbon tetrachloride appeared to be the best extractants. The absorption spectrum of Fe (II)-DM-Am complexes in chloroform shows maximum absorbance at 552-583 nm. It was observed that the color development was instantaneous and stable. Linear calibration graphs were obtained for 0.03-4.2 μg mL −1 of Fe.The molar absorptivity calculated was found to be (3.08-4.33) × 104 dm3 mol−1 cm−1 and the sensitivity of the method as defined by sandal's was 1.29-1.82 ng cm-2. The stoichiometry of the complex is established as 1:1:2 (M : L : Am) by equilibrium shift method, and confirmed the methods of relative yield, Asmus straight line and the intersection curves. It may be satisfactorily applied for the determination of Fe(III) with present method. The results of the prescribed procedure applied for the determination of the micro amounts of iron in pharmaceutical, biological, water, food and in plant samples are presented.read more

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Kuliev Kerim Avaz, Verdizade Nailya Allahverdi and Mamedova Shafa Aga

Study on Solvent Extraction Behavior of Rubidium by t-BAMBP-Sulphonated Kerosene System from Salt Lake Brine

The system of 4-tert-butyl-2-(α-methyl benzyl) phenol (t-BAMBP) and sulphonated kerosene (SK) solution was used to extract rubidium from Salt Lake Brine which has been removed the Mg2+ by precipitatation method. Several experimental parameters such as the concentration of t-BAMBP, hydroxide ion and stripping acid, the volume ratio of organic phase to aqueous extraction phase (O/A) and extraction stage were investigated. The obtained results showed that extraction efficiency of Rb+can reach 96% after five -stage, and the stripping efficiency of Rb+ can reach 99% after two-stage. And the extraction equilibrium constant K is calculated to be 25.85, enthalpy change is -20.79 kJ mol-1 and the separation factor of five-stage extraction is 71.77. The system of t-BAMBP and SK could be fully regenerated by water and showed no significant decrease after ten extraction-stripping cycles, indicating that the extractant was stable and reusable. The presence of co-existing ions do not interfere with rubidium extraction, indicating the high selectivity of t-BAMBP and SK for rubidium ion. The method provides an idea for exploitation and utilization rubidium and has the important economically significant for industrialization extraction rubidium.read more

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Amin Bao and Qian zhiqiang